Look at the Dow's Big Winners So Far This Year

Six months into the year, the Dow Jones Industrials have delivered their best performance since the roaring bull market of the 1990s, with gains of almost 14% having sent the average up by more than 1,800 points. Even though the Dow lost ground in June -- the first down month all year -- it still posted a respectable 2% gain for the second quarter.

But some of the Dow's stocks have done even better than the overall average. Let's look at the four stocks that have more than doubled the return of the Dow so far in 2013, with an eye toward what could be coming next for these companies in the second half of the year and beyond.

Hewlett-Packard , up 76.2% Many investors don't understand how HP has managed to recover so strongly this year. After all, CEO Meg Whitman's turnaround strategy still has a long way to go before it completely plays out, and it's far from certain that HP will succeed in putting its PC legacy behind it and finding new avenues for strong growth. If you only look at 2013's stock performance in isolation, you might come to the conclusion that investors are betting everything on a home run from Whitman and her team.

The key to HP's gains, though, is the fact that the stock got beaten down so badly last year. As a result, even with the stock's gains, HP still carries a price that offers some margin of safety even if things don't go as well as its executive team hopes. Moreover, if things go well, there's still some upside left for new investors in HP.

Boeing , up 37.5% Ordinarily, when a company has a major product recall, it's bad news for the stock. Yet even though Boeing had to ground its brand-new 787 Dreamliner aircraft early this year, the company managed not only to fix the plane's battery problem and get the Dreamliner up and flying again but also to make its official launch of its stretched Dreamliner 787-10 at the Paris Air Show.

None of Boeing's problems kept airlines and aircraft leasing companies from making initial orders of the Dreamliner, and the company sees a multi-trillion-dollar opportunity for aircraft sales in a number of different areas, ranging from the fuel efficient 737 MAX line of single-aisle planes to an eventual potential updated 777X that could improve on the large airliner's fuel efficiency. All these opportunities give Boeing plenty of room to fly higher.

Microsoft , up 31.3% Almost all of Microsoft's gains have come in the past few months, as investors have finally gotten comfortable with the value proposition behind the stock. Despite persistent concerns about Windows 8, Microsoft recently announced plans to provide its Windows 8.1 update to address concerns raised by early adopters of the operating system. In addition, the company has made some progress in the mobile space, assuming the No. 3 spot convincingly.

Microsoft has plenty of work left to do, but even after the recent run-up, shares still fetch just 11 times forward earnings estimates. Growth potential from moving Office software to a subscription-based model as well as its Xbox One next-generation gaming console could provide the drivers necessary to push Microsoft to even new heights.

American Express , up 30.9% Payment processors thrive on improving economic prospects, and American Express owes its rise to all-time highs to the health of consumer spending. Even though its rivals in the card-network business have far greater transaction volume and cards issued, AmEx nevertheless has the edge in income, because it's willing to take on the credit risk of its cardholders.

AmEx has traditionally targeted upper-income customers, but expanding into the prepaid-card business should provide even more growth and expose the company's brand to a new demographic group. That could spell even greater profits down the road.

Where will the Dow go?Recent turbulence in the broader market suggests that the Dow's second half might not be as lucrative as the first. Picking the right stocks, though, can get you better returns than the overall average, so be sure to look not just at how stocks have done so far in 2013 but whether they still have further reasons to move even higher.